Este trabalho tem como objetivo analisar e otimizar o desempenho de uma bomba hidráulica de fluxo através do redimensionamento de seu rotor. A partir da teoria acerca do pré-dimensionamento de rotores pelo método clássico (também conhecido como método geométrico) propõe-se uma planilha eletrônica que permite obter as dimensões básicas necessárias para o projeto de um rotor a partir de dados iniciais de operação e coeficientes empíricos. De modo a validar o dimensionamento teórico este trabalho apresenta um estudo de caso em uma bomba-teste. A partir dos dados do software de dimensionamento e recomendações coletadas na bibliografia um novo rotor é desenvolvido tendo como objetivo principal melhorar o desempenho de operação da bomba. Durante o desenvolvimento do novo rotor são utilizados aplicativos CAD e CAM de modo a auxiliar a elaboração do projeto e execução da usinagem. Uma bancada especial de teste de bombas é utilizada no levantamento dos dados experimentais. Os resultados dos ensaios demonstram um ganho máximo na eficiência de operação de 8% e redução de até 0,7 kW na potência da bomba operando com o novo rotor. / This work has as objective to analyze and to optimize the performance of a flow hydraulic pump by the re-design of pumps impeller. From the theory about impeller design by the classic method (also known as geometric method) proposes an electronic spread that allows obtaining the basic dimensions of impeller from initial pump operation data and empiric coefficients In order to validate the theoretical design this work presents a study of case on a pump test. From the design software data and recommendations collected in the bibliography review a new impeller is developed with the main objective to improve the pump performance. During the new impeller development are used applications CAD and CAM to aid the elaboration of the design and the execution of machining. A special hydraulic pump test bench is used to collect experimental data. The tests results shown a maximum gain of 8% in the efficiency of operation and a reduction of until 0,7 kW in the pump power consumption operating with the new impeller.

The problem of reference trajectory reconfiguration and long-term uncontrolled recovery of a formation of spacecraft is considered in an eccentric orbit under the influence of the J2 perturbation. Reference trajectories considered are the Projected Circular Orbit, Along-Track Orbit, and their eccentric modifications. Reconfiguration is accomplished using two, finite-pulse thrusts, modeled as impulses. The state transition matrix (STM) is calculated by four methods: (i) analytically from the Hill-Clohessy-Wiltshire equations, (ii) numerical integration using a fourth-order Runge-Kutta method, (iii) from the fundamental matrix of the linearized equations of motion, and (iv) computing the STM for the relative mean orbital elements, the geometric method. Only the geometric method takes into account J2, and it is shown to perform the transfers most accurately of all the methods. The methods are also applied to the reconfiguration maneuvers of the University of Toronto's CanX 4/5 formation flying mission.

The problem of reference trajectory reconfiguration and long-term uncontrolled recovery of a formation of spacecraft is considered in an eccentric orbit under the influence of the J2 perturbation. Reference trajectories considered are the Projected Circular Orbit, Along-Track Orbit, and their eccentric modifications. Reconfiguration is accomplished using two, finite-pulse thrusts, modeled as impulses. The state transition matrix (STM) is calculated by four methods: (i) analytically from the Hill-Clohessy-Wiltshire equations, (ii) numerical integration using a fourth-order Runge-Kutta method, (iii) from the fundamental matrix of the linearized equations of motion, and (iv) computing the STM for the relative mean orbital elements, the geometric method. Only the geometric method takes into account J2, and it is shown to perform the transfers most accurately of all the methods. The methods are also applied to the reconfiguration maneuvers of the University of Toronto's CanX 4/5 formation flying mission.

Este trabalho tem como objetivo analisar e otimizar o desempenho de uma bomba hidráulica de fluxo através do redimensionamento de seu rotor. A partir da teoria acerca do pré-dimensionamento de rotores pelo método clássico (também conhecido como método geométrico) propõe-se uma planilha eletrônica que permite obter as dimensões básicas necessárias para o projeto de um rotor a partir de dados iniciais de operação e coeficientes empíricos. De modo a validar o dimensionamento teórico este trabalho apresenta um estudo de caso em uma bomba-teste. A partir dos dados do software de dimensionamento e recomendações coletadas na bibliografia um novo rotor é desenvolvido tendo como objetivo principal melhorar o desempenho de operação da bomba. Durante o desenvolvimento do novo rotor são utilizados aplicativos CAD e CAM de modo a auxiliar a elaboração do projeto e execução da usinagem. Uma bancada especial de teste de bombas é utilizada no levantamento dos dados experimentais. Os resultados dos ensaios demonstram um ganho máximo na eficiência de operação de 8% e redução de até 0,7 kW na potência da bomba operando com o novo rotor. / This work has as objective to analyze and to optimize the performance of a flow hydraulic pump by the re-design of pumps impeller. From the theory about impeller design by the classic method (also known as geometric method) proposes an electronic spread that allows obtaining the basic dimensions of impeller from initial pump operation data and empiric coefficients In order to validate the theoretical design this work presents a study of case on a pump test. From the design software data and recommendations collected in the bibliography review a new impeller is developed with the main objective to improve the pump performance. During the new impeller development are used applications CAD and CAM to aid the elaboration of the design and the execution of machining. A special hydraulic pump test bench is used to collect experimental data. The tests results shown a maximum gain of 8% in the efficiency of operation and a reduction of until 0,7 kW in the pump power consumption operating with the new impeller.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Pretendemos, com esta dissertaÃÃo, enfatizar o problema da imaginaÃÃo no terceiro gÃnero de conhecimento na obra Ãtica de Benedictus de Spinoza (1632 â 1677). Na Parte II da Ãtica, o autor explicita os trÃs gÃneros de conhecimento: a imaginaÃÃo (o primeiro gÃnero), a razÃo (o segundo) e a ciÃncia intuitiva (o terceiro). Nossa hipÃtese à de que hà uma interaÃÃo entre o primeiro e terceiro gÃneros e que ocorre da seguinte forma: (1) pela preocupaÃÃo de Spinoza em usar a imaginaÃÃo para que a mente vincule as coisas exteriores ao contexto ontolÃgico da imanÃncia. E (2) pela inevitabilidade dos signos linguÃsticos (enquanto parte da imaginaÃÃo), sem os quais a potÃncia do intelecto (na ciÃncia intuitiva) nÃo seria capaz de comunicar o prÃprio sistema do autor. Faz-se necessÃrio, primeiramente, a explicaÃÃo do terceiro gÃnero de conhecimento e seu pressuposto ontolÃgico (substÃncia, atributos e modos). Essa exposiÃÃo somente à possÃvel pela mediaÃÃo das Partes I, II, III e V da obra aqui tratada. Posteriormente, analisa-se a imaginaÃÃo enquanto fonte de um conhecimento confuso especificamente na Parte II. No entanto, reconhecemos que ela prÃpria pode ser uma potÃncia, como Spinoza assinala na ProposiÃÃo XVII desta parte. Por fim, ao sobrepor imaginaÃÃo e ciÃncia intuitiva, depreendemos como hipÃtese que, em Ãltima instÃncia, a potÃncia da imaginaÃÃo està em seu vÃnculo direto com o terceiro gÃnero de conhecimento. Propomos, da mesma forma, que a ciÃncia intuitiva funda a ideia central da ontologia de Spinoza (ideia de Deus), da qual todas as outras sÃo deduzidas, conforme o mÃtodo geomÃtrico utilizado na Ãtica. Tal mÃtodo se funda na ciÃncia intuitiva e utiliza-se dos signos linguÃsticos, para comunicar sistematicamente a ontologia de Spinoza. / Our aim, with this work, is emphasize the problem of imagination in the third kind of knowledge in the work Ethics by Benedictus de Spinoza (1632-1677). In part II of Ethics, the author explicits the three kinds of knowledge: the imagination (the first kind), the reason (the second kind) and the intuitive science (the third). Our conjecture is that there is an interaction between the first and the third kinds and that this occurs as follows: (1) by the Spinozaâs preoccupation in use the imagination so that the mind links the external things to the ontological context of immanence. And (2) by the inevitability of linguistic signals (while part of imagination), without which the power of intellect (in intuitive science) would not be able to communicate the own authorâs system. It is necessary, first of all, the explanation of the third gender of knowledge and its ontological presupposition (substance, attributes and modes). This exposition is possible only by the mediation of Parts I, II, III and IV of the treated work. Posteriorly, is analyzed the imagination as source of a confused knowledge, specifically in Part II. However, we recognize that itself may be a power, as Spinoza notes in proposition XVII of this part. Finally, by superimposing imagination and intuitive science, we inferred as a hypothesis that, ultimately, the power of imagination is in direct bond with the third kind of knowledge. We propose, in the same way, that the intuitive science founds the central idea of ontology in Spinoza (idea of God), from which all the others are deduced, according to the geometric method utilized in Ethics. Such a method founds itself in the intuitive science and makes use of linguistic signals, to communicate systematically the Spinozaâs ontology.

In this dissertation, we study the interplay between a firm’s operations strategy, with regard to its capacity management, and its marketing decision of product differentiation. For this, we study a market comprising heterogeneous customers who differ in their preferences for time and price. Time sensitive customers are willing to pay a price premium for a shorter delivery time, while price sensitive customers are willing to accept a longer delivery time in return for a lower price. Firms exploit this heterogeneity in customers’ preferences, and offer a menu of products/services that differ only in their guaranteed delivery times and prices. From demand perspective, when customers are allowed to self-select according to their preferences, different products act as substitutes, affecting each other’s demand. Customized product for each segment, on the other hand, results in independent demand for each product. On the supply side, a firm may either share the same processing capacity to serve the two market segments, or may dicate capacity for each segment. Our objective is to understand the interaction between product substitution and the firm’s operations strategy (dedicated versus shared capacity), and how they shape the optimal product differentiation strategy. To address the above issue, we first study this problem for a single monopolist firm, which offers two versions of the same basic product: (i) regular product at a lower price but with a longer delivery time, and (ii) express product at a higher price but with a shorter delivery time. Demand for each product arrives according to a Poisson process with a rate that depends both on its price and delivery time. In addition, if the products are substitutable, each product’s demand is also influenced by the price and delivery time of the other product. Demands within each category are served on a first-come-first-serve basis. However, customers for express product are always given priority over the other category when they are served using shared resources. There is a standard delivery time for the regular product, and the firm’s objective is to appropriately price the two products and select the express delivery time so as to maximize its profit rate. The firm simultaneously needs to decide its installed processing capacity so as to meet its promised delivery times with a high degree of reliability. While the problem in a dedicated capacity setting is solved analytically, the same becomes very challenging in a shared capacity setting, especially in the absence of an analytical characterization of the delivery time distribution of regular customers in a priority queue. We develop a solution algorithm, using matrix geometric method in a cutting plane framework, to solve the problem numerically in a shared capacity setting. Our study shows that in a highly capacitated system, if the firm decides to move from a dedicated to a shared capacity setting, it will need to offer more differentiated products, whether the products are substitutable or not. In contrast, when customers are allowed to self-select, such that independent products become substitutable, a more homogeneous pricing scheme results. However, the effect of substitution on optimal delivery time differentiation depends on the firm’s capacity strategy and cost, as well as market characteristics. The optimal response to any change in capacity cost also depends on the firm’s operations strategy. In a dedicated capacity scenario, the optimal response to an increase in capacity cost is always to offer more homogeneous prices and delivery times. In a shared capacity setting, it is again optimal to quote more homogeneous delivery times, but increase or decrease the price differentiation depending on whether the status-quo capacity cost is high or low, respectively. We demonstrate that the above results are corroborated by real-life practices, and provide a number of managerial implications in terms of dealing with issues like volatile fuel prices. We further extend our study to a competitive setting with two firms, each of which may either share its processing capacities for the two products, or may dedicate capacity for each product. The demand faced by each firm for a given product now also depends on the price and delivery time quoted for the same product by the other firm. We observe that the qualitative results of a monopolistic setting also extend to a competitive setting. Specifically, in a highly capacitated system, the equilibrium prices and delivery times are such that they result in more differentiated products when both the firms use shared capacities as compared to the scenario when both the firms use dedicated capacities. When the competing firms are asymmetric, they exploit their distinctive characteristics to differentiate their products. Further, the effects of these asymmetries also depend on the capacity strategy used by the competing firms. Our numerical results suggest that the firm with expensive capacity always offers more homogeneous delivery times. However, its decision on how to differentiate its prices depends on the capacity setting of the two firms as well as the actual level of their capacity costs. On the other hand, the firm with a larger market base always offers more differentiated prices as well as delivery times, irrespective of the capacity setting of the competing firms.

In this dissertation, we study the interplay between a firm’s operations strategy, with regard to its capacity management, and its marketing decision of product differentiation. For this, we study a market comprising heterogeneous customers who differ in their preferences for time and price. Time sensitive customers are willing to pay a price premium for a shorter delivery time, while price sensitive customers are willing to accept a longer delivery time in return for a lower price. Firms exploit this heterogeneity in customers’ preferences, and offer a menu of products/services that differ only in their guaranteed delivery times and prices. From demand perspective, when customers are allowed to self-select according to their preferences, different products act as substitutes, affecting each other’s demand. Customized product for each segment, on the other hand, results in independent demand for each product. On the supply side, a firm may either share the same processing capacity to serve the two market segments, or may dicate capacity for each segment. Our objective is to understand the interaction between product substitution and the firm’s operations strategy (dedicated versus shared capacity), and how they shape the optimal product differentiation strategy. To address the above issue, we first study this problem for a single monopolist firm, which offers two versions of the same basic product: (i) regular product at a lower price but with a longer delivery time, and (ii) express product at a higher price but with a shorter delivery time. Demand for each product arrives according to a Poisson process with a rate that depends both on its price and delivery time. In addition, if the products are substitutable, each product’s demand is also influenced by the price and delivery time of the other product. Demands within each category are served on a first-come-first-serve basis. However, customers for express product are always given priority over the other category when they are served using shared resources. There is a standard delivery time for the regular product, and the firm’s objective is to appropriately price the two products and select the express delivery time so as to maximize its profit rate. The firm simultaneously needs to decide its installed processing capacity so as to meet its promised delivery times with a high degree of reliability. While the problem in a dedicated capacity setting is solved analytically, the same becomes very challenging in a shared capacity setting, especially in the absence of an analytical characterization of the delivery time distribution of regular customers in a priority queue. We develop a solution algorithm, using matrix geometric method in a cutting plane framework, to solve the problem numerically in a shared capacity setting. Our study shows that in a highly capacitated system, if the firm decides to move from a dedicated to a shared capacity setting, it will need to offer more differentiated products, whether the products are substitutable or not. In contrast, when customers are allowed to self-select, such that independent products become substitutable, a more homogeneous pricing scheme results. However, the effect of substitution on optimal delivery time differentiation depends on the firm’s capacity strategy and cost, as well as market characteristics. The optimal response to any change in capacity cost also depends on the firm’s operations strategy. In a dedicated capacity scenario, the optimal response to an increase in capacity cost is always to offer more homogeneous prices and delivery times. In a shared capacity setting, it is again optimal to quote more homogeneous delivery times, but increase or decrease the price differentiation depending on whether the status-quo capacity cost is high or low, respectively. We demonstrate that the above results are corroborated by real-life practices, and provide a number of managerial implications in terms of dealing with issues like volatile fuel prices. We further extend our study to a competitive setting with two firms, each of which may either share its processing capacities for the two products, or may dedicate capacity for each product. The demand faced by each firm for a given product now also depends on the price and delivery time quoted for the same product by the other firm. We observe that the qualitative results of a monopolistic setting also extend to a competitive setting. Specifically, in a highly capacitated system, the equilibrium prices and delivery times are such that they result in more differentiated products when both the firms use shared capacities as compared to the scenario when both the firms use dedicated capacities. When the competing firms are asymmetric, they exploit their distinctive characteristics to differentiate their products. Further, the effects of these asymmetries also depend on the capacity strategy used by the competing firms. Our numerical results suggest that the firm with expensive capacity always offers more homogeneous delivery times. However, its decision on how to differentiate its prices depends on the capacity setting of the two firms as well as the actual level of their capacity costs. On the other hand, the firm with a larger market base always offers more differentiated prices as well as delivery times, irrespective of the capacity setting of the competing firms.